Apparatus for cutting thread in sewing-machines



i A. E. LINDNER.

APPARATUS FOR CUTTING THREAD IN SEWING MACHINES.

APPL]CATION FILED JAN-2.1915.

l 1 93,996 Patented Aug. 8, 1916.

2 SHEETSSHEET I- A. E. LINDNER.

APPARATUS FOR CUTTING THREAD IN SEWING MACHINES.

APPLICATION FILED JAN.2. 1915.

l ,1 93,906. Patented Aug. 8, 1916.

2 SHEETS-SHEET 2.

III/0 3 vweutoz ARTHUR E. LINDNER, OF BROOKLYN, NEW YORK.

APPARATUS FOR CUTTING THREAD IN SEWING-MACHINES.

Application filed January 2, 1915.

To all whom it may concern Be it known that I, ARTHUR E. LINDNER, acitizen of Germany, and a resident of Brooklyn, in the county of Kingsand State of New York, have invented certain new and useful Improvementsin Apparatus for Cutting Thread in Sewing-Machines, of which thefollowing is a specification.

This invention relates to apparatus for cutting thread in sewingmachines, and particularly those known as button sewingand button holemachines.

An object of the invention is to provide a cutting means by which twoonly of the three limbs formed by the two threads below the cloth andbutton or below the button hole, are cut, the third limb connected tothe needle being left whole.

A further object is to provide a cutting device by which after abutton-is sewed on a sure close cutting of the threads is accomplished,and the correct lengths of thread are left from the needle and bobbinfor the neXt sewing operation.

With these and other objects in view my invention consists of the novelfeatures, construction and combination of parts, hereinafter more fullydescribed and pointed out in the claims.

In the drawings, Figure 1 is a side elevational view of a button sewingmachine embodying my invention, Fig. 2 is a top plan view of the bedplate thereof with button holding attachment removed, Fig. 8 is asectional detail view showing the position of the threads at thebeginning of the sewing of a button, Fig. 1 is a similar view showingthe position of the threads when the sewing of a button is completed,Fig. 5 is an end view of the arrangement shown in Fig. 4, and Figs. 6, 7and 8 are details of the cutting device.

Similar reference characters indicate corresponding parts throughout theseveral views.

Referring to the drawings and more particularly to Fig. 1 thereof, abutton sewing machine 1 of well-known construction is provided with aneedle 2, having reciprocating rectilinear movement, adapted toalternately pass through each hole of a button, and a button'holder 8adapted to be raised and lowered from the cloth in a manner well-known.Longitudinally of the bedplate 4 of the machine is provided a slot 5 inwhich is sildably mounted a bar 6 at the Specification of LettersPatent.

Patented Aug. 8, 1916.

Serial N0. 238.

end of which is secured the cutting member 7 The said bar isreciprocated by means of a bell crank lever 8 pivoted to the bed plateat 9, and connected to the said bar by a lever 10 pivoted at 11 and alink 12. A screw 13 and wing nut 14 are fitted into the handle 15 of thelever 8 for adjusting the position of the bar 6. A spring 16 is securedbetween the said bell crank lever and the bed plate of the machine tohold the same in non-operating position, and 'a stop 17 is secured tothe bed plate to limit the movement of the said bell crank lever. Theend of the cutting member-7 projects into the opening 18 of the bedplate so that it rests under the cover plate 19 thereof just behind thelongitudinal opening 20 therein for the passage of the needle 2. Alongitudinal slot 21 is provided centrally of the cutting member inalinement with the opening 20, which embraces during operation the limbof thread from the needle, not to be out. At either side of the saidslot are provided inwardly inclined knife edges 23 and 24 which recedeto the base of the curved side walls of the forwardly projectingportions 25 and 26. Forwardly of the opening 20 is provided the threadguiding member 27 adapted to be moved rearwardly by operation of the bar28. The said guiding member is provided with a short slot 29 inalinement with the slot 21 of the cutting member and the opening 20, andto either side of the said slot there are provided thread guidingsurfaces for guiding the limbs of thread in the path of the cuttingedges 23 and 24. The guiding surface 30 for the bobbin limbs of thread,which is cut by the cutting edge 24-, is arcuate in shape, the limbbeing guided. outwardly to the lower point of the are which is in thepath of the said cutting edge 24. The guiding surface 31 for the needlelimb of thread is inclined to a notch 32 in the path of the cutting edge23, the limb being guided into the said notch where it is securely heldto be cut. The center limb of thread from the needle is untouched duringthe cutting operation, the same being embraced by the walls of slots 21of the cutting member, and 29 of the guiding member.

In Figs. 3, A and 5 of the drawings I have shown a button 33 being sewedto a piece of cloth, and I have shown diagrammatically the circularbobbin 85, oscillating shuttle 36 and oscillating driver 37 of thewell-known type. The two limbs of thread forming the loop from theneedle are indicated in the drawings as A and B, the former being thecenter or uncut limb and the latter the limb to be out, and the bobbinlimb of thread is indicated as C.

The operation of my improved cutting device is as follows :-The button33 is sewed on to the cloth in the well known manner, the position ofthe limbs of thread at the beginning of the operation being indicated inFig. 3 and at the end of the operation in Figs. 2, 4, 5 and 6, the limbA being in the center and the limbs of thread B and C at either sidethereof. When the proper number of stitches have been made to sequre thebutton to the cloth, the needle 2 is auto-' matically stopped, theguiding member 27 is brought from the position shown in Fig. 6 to thatshown in Figs. 7 and 8, and the button holder is lifted to release thecloth, by operation of the cam wheel 38 shown in Fig. 1, which revolvesonce for each button sewed. At the end of its revolution a projection 39thereon pushes upward the end of a rod 40 loosely mounted on the shaft41, thereby causing the forward end of the rod to be lowered andreleasing the lever 42 normally held in position in the recess 43 of therod 40 by a pin 44 thereon. The movement of the rod 40 causes theforward movement of the belt shifting member 61 which shifts the belt 62from the pulley 63 to the pulley 64, causing the automatic stopping ofthe needle. The lever 42 is connected by a link 42 to an arm 42 which iskeyed to the shaft 41. The lower end of the said lever is connected to ashiftable shaft 46 provided at the ends with beveled gears 47 and 48.When the lever 42 is released, the said shaft 46 is shifted by means ofa spring 49, so that the beveled gear 47 meshes with a beveled gear 50,which is constantly driven by the driving mechanism, and the bevel gear48 meshes with a beveled gear 51 carried by a cam disk 52, which is thencaused to rotate. An eccentric cam groove 53 is provided in the disk 52,which is engaged by an anti-friction roller 54 carried on the end of thebar 28, so that when the disk 52 is rotated the bar 28 and the guidemember 27 are moved forwardly. Simultaneously with this action, an arm55 also keyed to the shaft 41, is moved forwardly. This arm 55 isconnected by means of a rod 56 to one arm of an elbow lever 57 pivotedat 58 to the frame, 1. The other arm is provided with a forked end 59which engages an upwardly extending portion 60 of the button holder, andcauses the same to be raised.

As the guiding member 27 is being brought forward it engages the limbsofthread A, B and G, embracing the center limb A and guiding outwardly thelimbs B and G into the path of the cutting edges 23 and 24. The handle15 of the lever 8 is operated to thrust the cutting member 7 forwardly,thereby cutting the limbs B and C and leaving the thread A whole, byreason of the slot 21. WVhen so cut, the spring 16- serves to draw thecutting member back into position, and a handle 45 shown 111. Fig. 1

which is connected to the shaft 41 is de-- pressed to reset the machinefor sewing on the next button.

I have shown a preferred and satisfactory embodiment of my invention,but it is obvious that changes may be made therein without departingfrom the spirit and scope thereof as defined in the appended claims.

I claim:

1. A thread cutting device for sewing machines, comprising a cuttingmember consisting of a single plate, provided with an elongated slottherein, adapted to embrace one limb of thread notto be cut, cuttingedges at either side of said slot adapted to cut limbs of thread notembraced by said slot and means for moving said cutting member intoengagement with the said thread. p

2. A thread cutting device for sewing machines, comprising a cuttingmember provided with a longitudinal slot adapted to embrace one limb ofthread not to be cut, inclined cutting edges at either side ofsaid slotadapted to cut limbs of thread not em-.

braced by said slot and means for reciprocating sald cutting member.

3. A thread cutting device for sewing chines, comprising a cuttingmember, provided with a longitudinal slot, adapted to embrace one limbof thread not to be cut, in clined cutting edges at either side of saidslot adapted to cut limbs of thread not. 8111-.

braced by said slot, means for reciprocating said cutting member, andguiding means adapted to move said limbs in the path of said slot andcutting edges.

4. A thread cutting device for sewing machines, comprising a cuttingmember having as my invention, I have signed my name in presence of twosubscribing witnesses. I

ARTHUR E. LINDNER. Witnesses:

F. Hose, D. LnwIs MATTERN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner .of Patents;

Washington, D. C.

